Tests of a full-sized mechanically rechargeable zinc-air battery inan electric vehicle

A mechanically rechargeable zinc-air battery that has high power density and fast refueling capability is described. The battery is built from modules of 32 or 44 cells connected in series, and the modules can be arranged in any combination of series and parallel connections, and in practical quantity, according to the requirements of the vehicle, motor, and controller. The results of laboratory and in-vehicle tests of a zinc-air battery consisting of two 32-cell modules connected in series, with nominal voltage of 75 V and nominal capacity of 216 Ah, are presented     

A microcontroller-based intelligent battery system

State-of-charge indication for a secondary battery is becoming increasingly important for battery-operated electronics. Consumers are demanding fast charging times, increased battery lifetime, and fuel gauge capabilities. All of these demands require that the state of charge within a battery be known. One of the simplest methods employed to determine state of charge is to monitor the voltage of the battery. However, this method alone is not a good indicator of battery energy, since both NiMH and NiCd batteries have voltage-versus-energy curves that are essentially flat. This paper presents a more effective method of determining the state of charge in secondary cell batteries. A NiMH battery is used as our test vehicle, since it is one of the more difficult batteries to determine state of charge. This method monitors the battery's temperature, voltage, and discharge/charge rate. A microcontroller then manipulates the information, using look-up tables to determine the state of charge. Also, by modifying the look-up tables, this technique can be employed in many other battery technologies and is not limited to NiMH     

Global avionics in the future

The following topics are discussed: new batteries for old airplanes; new charge controls for lengthening battery life; fast methods for batteries charging; AC conductance measurement based battery testing; pulse power; bipolar lead-acid batteries vs supercapacitors; Ni electrode cells for spacecraft; worn-out battery disposal; recycling technology; vehicle batteries cost; high energy content batteries; and energy storage for electric utilities     

Demonstration of a zinc bromine battery in an electric vehicle

The zinc bromine battery is a high energy density battery that utilizes low cost materials. The battery is of unique construction utilizing plastic storage tanks for the zinc bromide electrolyte and plastic bipolar electrode stacks. This paper briefly describes the zinc bromine battery technology and the experience gained in installing and operating an electric vehicle with this advanced system. The described electric vehicle (The “T-Star”) was tested in March 1993 on the Chrysler Proving Grounds in Phoenix, Arizona and it participated in the May 1993 American Tour de Sol capturing second place over all and first place in the student division     

An energy management system to improve electric vehicle range andperformance

An electric vehicle (EV) energy management system (EMS) developed to accurately predict and extend the usable driving range and the life of the battery pack is discussed. The EMS monitors and records battery state of charge, vehicle performance, power consumption of key components, and driver's actions. Convenient drive inputs in conjunction with memorized energy consumption profiles allow accurate prediction of driving range and selection of appropriate recharging profiles. EV range extension is accomplished by identifying inefficient use of energy, resulting in EMS modification of energy usage by offending subsystems or EMS suggestion to the driver of improved driving habits or vehicle use. Factors affecting the accuracy of range prediction and the amount of range extension are described     

Ultracapacitors + DC-DC converters in regenerative braking system

An ultracapacitor system for an electric vehicle has been implemented. The device allows higher accelerations and decelerations of the vehicle with minimal loss of energy and minimal degradation of the main battery pack. The system uses a DC-DC power converter, which is connected between the ultracapacitor and the main battery pack. The design has been optimized in weight and size, by using water-cooled heat sinks for the power converter, and an aluminum coil with air core for the smoothing inductance. The ratings of the ultracapacitor are: nominal voltage: 300 Vdc; nominal current: 200 Adc; capacitance: 20 Farads. The amount of energy stored allows us to have 40 kW of power during 20 seconds, which is enough to accelerate the vehicle without the help of the traction batteries. The vehicle uses a brushless DC motor with a nominal power of 32 kW and a peak power of 53 kW. A control system based on a Digital Signal Processor (DSP) manipulates all the aforementioned variables and controls the Pulse Width Modulation (PWM) switching pattern of the converter transistors. The car used for the implementation of this system is a Chevrolet LUV truck.     

Fast intelligent battery charging: neural-fuzzy approach

This paper focuses on the design of a super fast battery charger based on National's proprietary neural network based NeuFuz technology. In this application, we have used a NiCd battery pack as the test vehicle. However, this technology can be extended to other chemistries such as Ni-MH, Li-ion, etc. This technology allows the designer to accurately model the charge controller using a neural network, based on battery charge characteristics provided by the manufacturer. This approach continuously monitors the battery status, and modifies the charge current accordingly. It also eliminates the need for standard charge termination methods used in today's conventional chargers. The result is super fast charging in 20 to 30 minutes, and increased battery life. A low cost embedded controller (COP8) performs all the fuel-gauging and charge control functions by processing data obtained from the battery circuitry     

Battery charge controller characteristics in photovoltaic systems

Typical strategies for battery charge regulation and load control in stand-alone photovoltaic (PV) systems are presented. Several charge algorithms (methods of controlling current to the battery) are presented, along with terminology used by the PV industry for battery charge controllers. Information gained from an extensive evaluation of commercially available charge controllers and data collected from tests on PV systems in the field are discussed. An overview of battery performance characteristics needed for the successful design and long-term operation of PV systems is presented with the intent of soliciting feedback on the information presented from the battery industry     

无人机车辆组合物流配送路径规划探讨

近年来无人机在各个领域的应用逐渐兴起,尤其是在物流运输领域发展迅速。在物流运输领域的应用主要是与车辆进行组合运输,国内外的学者针对无人机和车辆组合运输的路径规划问题进行了许多研究。主要论述了目前车辆和无人机组合运行的4种模式,包括车辆支持无人机运行模式、无人机支持车辆运行模式、无人机与车辆独立的运行模式、无人机和车辆同步的运行模式。探究了目前无人机和车辆组合路径规划问题考虑的因素,包括无人机电池电量、运送包裹数量和时间窗等。对有无人机参与的车辆路径规划问题的目标优化进行了总结,目前的研究主要分为3类,包括考虑最短配送时间、最小总成本和多目标规划。这些研究对未来无人机配送问题的研究具有重要的指导意义。     

Market mature 1998 hybrid electric vehicles

Beginning in 1990, the major automotive passenger vehicle manufacturers once again re-evaluated the potential of the battery powered electric vehicle (EV). This intensive effort to reduce the battery EV to commercial practice focused attention on the key issue of limited vehicle range, resulting from the low energy density and high mass characteristics of batteries, in comparison to the high energy density of liquid hydrocarbon (HC) fuels. Consequently, by 1995, vehicle manufacturers turned their attention to hybrid electric vehicles (HEV). This redirection of EV effort was highlighted finally in 1997, at the 57th Frankfurt Motor Show, the Audi Duo parallel type hybrid was released for the domestic market as a 1998 model vehicle. Also at the 1997 32nd Tokyo Motor Show, Toyota Hybrid System (THS) Prius was released for the domestic market as a production 1998 model vehicle. This paper presents a comparative analysis of the key features of these two 1998 model year production hybrid systems. Among the conclusions, two issues are evident: one, the major manufacturers have turned to the hybrid concept in their search for solutions to the key EV issues of limited range; and, heating/air conditioning; and two, the focus is now on introducing hybrid EV for test marketing domestically     

不同进出风模式和电池组位置的电动汽车气动性能分析

采用GAMBIT软件作为前处理器,应用FLUENT软件作为计算和后处理软件,对不同进出风模式和电池组位置的电动汽车气动性能进行分析,研究表明:单口上出风模式的电动汽车气动性能最佳,下出风口模式的气动性能最差;随着电池组与动力舱后壁距离增加,电动汽车气动性能先改善,再变差,满足电动汽车最优气动性能的距离为230mm.      

Charge measurement circuit for electric vehicle batteries

Calculating the state of charge (SOC) of an electric vehicle (EV) battery is an inherently error prone process that depends on several variables. However, the accuracy of the required charge flow measurements can be greatly improved by using a voltage to frequency (V/F) converter in conjunction with a digital counter to integrate the measured battery current.     

Commercialization of advanced batteries

Mader & Associates has been working as a contractor for the South Coast Air Quality Management District (District) as well as domestic and off-shore battery developers for the past several years. During this period, it has performed various assessments of advanced battery technology as well as established the Advanced Battery Task Force. The following paper is Mader's view of the status of battery technologies that are competing for the electric vehicle (EV) market being established by the California Air Resources Board's Zero Emission Vehicle (ZEV) mandate. The ZEV market is being competed for by various advanced battery technologies. And, given the likelihood of modifications to the Mandate, the most promising technologies should capture the following market share during the initial 10 years: lead-acid-8.4%; nickel metal hydride-50.8%; sodium nickel chloride-7.8%; and lithium ion-33.0%. However, today there is much less certainty associated with EV market prediction due to changes in the ZEV regulations     

容错航空蓄电池电源及其均衡管理

航空蓄电池在实际使用中会出现电池性能衰退与退化速率不一致,电池组容量与使用寿命降低,甚至可能出现严重的安全事故。针对电池单体不一致性和故障隔离问题,提出一种蓄电池电源系统容错体系结构和分级容错控制策略,提出基于电池单体动态重构的主动均衡管理新方法,设计基于"冒泡沉底（BS）择优上岗"的电池单体实时动态重构策略。开发容错航空镍镉电池电源原理样机,给出系统实验性能分析,实验结果表明所提出的系统技术方案可行有效,能够快速隔离故障失效电池单体,明显改善电池不一致性,提高了电池组容量利用率和剩余使用寿命。     

天宫号目标飞行器氢镍蓄电池压力-容量充电控制研究简

作为在轨管理的关键部分,良好的充电控制是保证蓄电池长寿命的重要因素.对于氢镍蓄电池,压力-容量充电控制是最理想的充电控制方式,但存在压力检测难度大、控制策略复杂等困难.天宫一号目标飞行器氢镍蓄电池通过大量的压力测量地面可靠性试验,解决了压力传感器的测量稳定性及一致性问题;同时提出柔性充电控制策略,给出了压力-容量标准曲线、不同荷电态下的充电电流及压力控制点修正系数.在轨数据表明,天宫一号目标飞行器氢镍蓄电池压力-容量充电控制稳定,满足设计要求.     

微型纯电动汽车动力舱风冷散热研究

微型纯电动汽车的进风口可以布置在多个位置,将进风口布置在微型纯电动汽车动力舱前端,研究这种进风方式的散热效率;不同进出风模式是否可以改善动力舱的散热性能也是一个值得关注的问题.研究结果表明:电池组发热量、车外环境温度及进风温度对动力舱内的温度影响较大,进风口数目及动力舱进风速度对其影响较小;当进风温度低于环境温度时,增加进风口数目和提高车速可以提高散热性能,当进风温度高于环境温度时,减少进风口数目和降低车速可以提高散热性能.上述结论为微型纯电动汽车动力舱散热方案实施提供了参考依据.      

A nickel/hydrogen battery for PV systems

The nickel-hydrogen battery, developed in the early nineteen-seventies as an energy-storage subsystem for commercial communication satellites, is discussed. The advantages offered by nickel-hydrogen batteries, including long life, low maintenance and high reliability, make it very attractive for terrestrial applications such as stand-alone photovoltaic systems. The major drawback to the wider use of the nickel-hydrogen battery is its high initial cost. A 7-kWh battery has been on test since January 1988 using a flat-plate photovoltaic array for charging. The cell, battery design and test methods are briefly described, and the results of cycling and solar tests are presented. It is concluded that the battery is well suited for remote solar applications     

Heating and cooling battery electric vehicles-the final barrier

Battery electric vehicles (EVs) present a particular challenge to the development of more efficient and effective heating and cooling systems for automotive applications. Because heating-ventilating-air-conditioning (HVAC) systems are electrically powered, vehicle range is reduced when the HVAC system is operating. The alternative solutions to HVAC battery electric vehicles are identified and evaluated. These include a basis for determining HVAC boundary design assumptions and showing mathematical methods for estimating the HVAC load and energy requirements, and evaluation of the new European and Japanese approaches to wintertime heating, such as NaS battery, motor and component waste heat recovery, electric seat warmer, radiant foot warmer, electric windshield and backlight defrost, molten salt latent heat storage, metal hydride hydrogen storage and catalytic heater, and liquid fueled heater     

Battery package design optimization for small electric aircraft

The increasing gross weight of electric Unmanned Aerial Vehicle (UAV) poses a challenge in practical applications. The range and endurance of the electric UAV are limited by the fixed mass of the battery package. In this work, a design optimization method for the battery package topology of small electric UAV is proposed to enhance the performance. To improve the accuracy of the method, the dynamic battery model and simplified electric component models are presented. These models are utilized by the trajectory optimization method, which takes the dynamic characteristic into consideration to calculate the aircraft performance. The direct optimal control method is used for solving the trajectory optimization problem, and this method is tested on a small blended-wing-body electric aircraft. The test result shows that the range and energy-consumption are mainly influenced by the parallel topology of the battery package, while the flight time in climb phase is more sensitive to the series topology. It is deduced that the range- and energy-optimal design points can be considered concurrently in design optimization. The work proves the feasibility of integrating the trajectory optimization and battery package design.     

可变弯尾飞行器布局气动特性分析

本文研究了可变弯尾飞行器的气动布局设计问题，并计算分析了此类飞行器的气动特性，提出了气动设计的关键问题。可变弯尾飞行器具有结构简单、气动热环境良好、气动控制独特、机动范围可调等特点，是高超声速飞行器实现机动飞行的有效途径。弯尾部分产生的铰链力矩是此类飞行器的设计关键。通过研究分析器的质心位置、弯尾部分的尾长和弯尾角的相互关系，获得了使铰链力矩在飞行器较大配平范围内保持可接受程度的可变弯尾飞行器气动布局。